85 Merc 150 XR2 Black Max

[bassinbob_123]

Having some issues with throttle.. SN A114595
Replaced the packs and thought maybe I had a bad 'new' unit. Changed the inner pack and now the tach works but -- went out this morning to check the repairs and I had trouble coming onto plane. Motor wont go above 4000.?? Could this be a bad trigger as I suspect the two center holes are not firing. Engines runs good and flat with no misses but just wont come up to rpm..

Suggesstions Please

Bob

 

[Bassin_Bob123]

Re: 85 Merc 150 XR2 Black Max

Having some issues with throttle.. SN A114595
Replaced the packs and thought maybe I had a bad 'new' unit. Changed the inner pack and now the tach works but -- went out this morning to check the repairs and I had trouble coming onto plane. Motor wont go above 4000.?? Could this be a bad trigger? I do not have fire to #3 hole but all the rest. New plug and changed #5 with #3 plug. Still no fire. Changed coils with a know good coil but still no fire. Suggesstions Please

Bob

Added info

 

[Dukedog]

Re: 85 Merc 150 XR2 Black Max

Check tha stator first then trigger then switch boxes.
Tach (grey wire) should come from either of tha yellow wires on tha rectifier....

 

[Bassin_Bob123]

Re: 85 Merc 150 XR2 Black Max

Thanks Duke Dog. Will start there...

Bob

 

[sschefer]

Re: 85 Merc 150 XR2 Black Max

1. Disconnect the Yellow wires from the stator to the rectifier and retest. If the engine now has good spark, replace the
rectifier.
2. Disconnect the idle stabilizer (advance module) and reset the timing between 23-25 degrees Wide Open Throttle. If the problem clears, discard the idle stabilizer as it is not needed.
3. Connect a DVA meter between the stator?s Blue wire and engine ground. Run the engine up to the RPM where the problem is occurring. DVA voltage should increase with RPM. A sharp drop in DVA right before the problem occurs usually indicates a bad stator. (Repeat the test from Blue/White to engine ground and compare the readings).
4. Connect a DVA meter between the stator?s Red wire and engine ground. The DVA voltage should show a smooth climb in voltage and remain high through the RPM range. A reading lower than on the Blue wire reading indicates a bad stator. (Repeat the test from Red/White to engine ground and compare the readings).
5. If all cylinders become intermittent, replace both switch boxes.
6. Connect an inductive tachometer to each cylinder in turn and try to isolate the problem. If two or more cylinders on the same bank are dropping out, the problem is likely going to be either the stator or the switch box. A single cylinder dropping spark will likely be a bad switch box or ignition coil. All cylinders not sparking properly usually indicates a bad stator.
7. Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a miss at high speed when the water pressure gets high, but a normal shutdown will mask the problem.
8. Check the triggering and charge coil flywheel magnets for cracked, broken and loose magnets.

Provided courtesy of CDI Electronics http://www.cdielectonics.com

http://www.cdielectronics.com/downl...eshooting Guide 2009 - Mercury 6 Cylinder.pdf​

 

[Bassin_Bob123]

Re: 85 Merc 150 XR2 Black Max



WOW! A huge thanks SSCHEFER. I was looking for somethiung on this exact method but my Merc book or another Seslock book didn't show the procedure.

With only #3 dead, I will 1st do the stator test, then change the box.

A question:: I am getting the same issue changing the outer box to the inner box. Still thinking now that my theroy and your suggestion being it's a stator if not the triiger assy. Leading to the stator and checking for crackes and flaws..

M U C H A P P R E C I A T E D !!

Bob